5' copyback defective viral genomes are major component in clinical and non-clinical influenza samples.

Clinical samples from people with influenza disease have been analyzed to assess the presence and abundance of Defective Viral Genomes (DVGs), but these have not been assessed using the same bioinformatic pipeline. The type of DVG most described for influenza infections (deletion DVGs) differs from the most commonly described DVGs from non-segmented negative stranded viruses (5' copyback). This could be attributed to either differences between viruses or the tools used to detect and characterize DVGs. Here we analyze several NGS datasets from people infected with different types of influenza virus using the same bioinformatic pipeline. We observe that 5' copyback DVGs are prevalent in all human clinical samples but not in the cultured samples. To address this discrepancy between clinical and laboratory cultures, we infected cell culture and ferrets with an H5N8 influenza A virus (FLUAV) and analyzed the DVG composition. The results demonstrate that the DVG population is skewed toward 5' copyback DVGs in the in vivo infections and deletion DVGs in the in vitro infections. This demonstrates that there are differences in vivo genome production and in vitro genome production, and this has implications for how the role of DVGs in clinical disease is studied. We also investigate the role the host cofactor ANP32B has in DVG production.

Spatial and temporal dynamics and fluxes estimation of manganese fractions in sediments from the Pearl River Estuary, southern China.

Sequential extraction was used to study the historical dynamics and fluxes of the chemical fractions of manganese (Mn) in sediments collected from the Pearl River Estuary (PRE), southern China. Results revealed that the proportion of Mn associated with different fractions decreased in the order of acid-soluble fraction (F1) > reducible fraction (F2) > residual fraction (F4) > oxidizable fraction (F3). F1 (47%) was the dominant Mn fraction, indicating the strong bioavailability of Mn to aquatic organisms in the PRE. In addition, the Mn fraction F2 was present at an average rate of 27.93 % in surface sediments, indicating that it could be mobilized when environmental conditions become increasingly reducing or oxidizing. The decline in Mn fraction fluxes after 2006 indicated that the region has partially decreased due to the removal of heavily polluting industries and effective control of sewage discharge.

Glycosylation of H4 influenza strains with pandemic potential and susceptibilities to lung surfactant SP-D.

We recently reported that members of group 1 influenza A virus (IAV) containing H2, H5, H6, and H11 hemagglutinins (HAs) are resistant to lung surfactant protein D (SP-D). H3 viruses, members of group 2 IAV, have high affinity for SP-D, which depends on the presence of high-mannose glycans at glycosite N165 on the head of HA. The low affinity of SP-D for the group 1 viruses is due to the presence of complex glycans at an analogous glycosite on the head of HA, and replacement with high-mannose glycan at this site evoked strong interaction with SP-D. Thus, if members of group 1 IAV were to make the zoonotic leap to humans, the pathogenicity of such strains could be problematic since SP-D, as a first-line innate immunity factor in respiratory tissues, could be ineffective as demonstrated in vitro. Here, we extend these studies to group 2 H4 viruses that are representative of those with specificity for avian or swine sialyl receptors, i.e., those with receptor-binding sites with either Q226 and G228 for avian or recent Q226L and G228S mutations that facilitate swine receptor specificity. The latter have increased pathogenicity potential in humans due to a switch from avian sialylα2,3 to sialylα2,6 glycan receptor preference. A better understanding of the potential action of SP-D against these strains will provide important information regarding the pandemic risk of such strains. Our glycomics and in vitro analyses of four H4 HAs reveal SP-D-favorable glycosylation patterns. Therefore, susceptibilities to this first-line innate immunity defense respiratory surfactant against such H4 viruses are high and align with H3 HA glycosylation.

The research on CO oxidation over Ce-Mn oxides: The preparation method effects and oxidation mechanism.

A series of CeO2-MnOx for highly efficient catalytical oxidation of carbon monoxide were prepared by citrate sol-gel (C), hydrothermal (H) and hydrothermal-citrate complexation (CH) methods. The outcome indicates that the catalyst generated using the CH technique (CH-1:8) demonstrated the greatest catalytic performance for CO oxidation with a T50 of 98 °C, and also good stability in 1400 min. Compared to the catalysts prepared by C and H method, CH-1:8 has the highest specific surface of 156.1 m2 g-1, and the better reducibility of CH-1:8 was also observed in CO-TPR. It is also observed the high ratio of adsorbed oxygen/lattice oxygen (1.5) in the XPS result. Moreover, characterizations by the TOF-SIMS method indicated that obtained catalyst CH-Ce/Mn = 1:8 had stronger interactions between Ce and Mn oxides, and the redox cycle of Mn3++Ce4+ ↔ Mn4++Ce3+ was a key process for CO adsorption and oxidation process. According to in-situ FTIR, the possible reaction pathway for CO was deduced in three ways. CO directly oxidize with O2 to CO2, CO adsorbed on Mn4+ and Ce3+ reacts with O to form intermediates (COO-) (T > 50 °C) and carbonates (T > 90 °C), which are further oxidized into CO2.

Spatial and Temporal Variations and Risk Assessment of Heavy Metal Fractions in Sediments of the Pearl River Estuary, Southern China.

Sequential extraction was used to study the mobility and ecological risk of chemical fractions of six heavy metals in sediments collected from the Pearl River Delta (PRE) in China. Results revealed that residual fractions (F4) were the dominant forms for Cr and Ni in surface sediments, indicating that they were primarily stable in nature and had low bioavailability and ecotoxicity. Cd had a high environmental risk owing to its higher availability in acid-soluble fraction (F1), whereas Pb occurred predominantly in the reducible fraction (F2) in surface sediments. The profile variations of bioavailable fractions were generally consistent with socioeconomic development in the Pearl River Delta (PRD). A decreasing trend after 2006 suggested a reduction in heavy metal bioavailable fractions owing to the removal of heavy polluting industries and the effective control of sewage discharge. The risk assessment code suggested that the high mobility of Cd posed an extremely high risk and a threat to the aquatic environment.

Harmless process of organic matter in organosilicon waste residue by fluidization-like DDBD reactor: Temperature action and mechanism.

Herein, the non-hazardous application of low-temperature plasma technology in solid waste from the silicone industry was investigated by using a fluidization-like double dielectric barrier discharge plasma (DDBD) reactor. The results show ∼92.9% TOC in the organosilicon waste residue could be removed at the conditions (Discharge power: 7.0 W, S/G: 12.5 gminL-1, SIE: 158.0 JL-1), i.e. TOC content decreases from 166.0 g/kg to 11.8 g/kg. At the same time, the energy efficiency of the TOC removal rate reach ∼732.1 gkWh-1, and the temperature of the discharge zone is below 280 °C. According to the TG-MS analysis and infrared thermal imager, it is considered that the heat energy generated in the plasma treatment process can affect the decomposition of organic matter. On the other hand, the samples were characterized before and after treatment by BET, SEM, XRD, FTIR, and GC-MS. It was proposed the organic matter was firstly gasified under the action of plasma and thermal. Then, the active group will generate and react with the C-H, C-C, or C-Si by the bombardment of sufficient energy of charged particles, leading the organic matter further to decompose into small molecules, such as CH4, H2, CO, and CO2.

Post-vaccination serum cytokines levels correlate with breakthrough influenza infections.

Post-vaccination cytokine levels from 256 young adults who subsequently suffered breakthrough influenza infections were compared with matched controls. Modulation within the immune system is important for eliciting a protective response, and the optimal response differs according to vaccine formulation and delivery. For both inactivated influenza vaccine (IIV) and live attenuated influenza vaccines (LAIV) lower levels of IL-8 were observed in post-vaccination sera. Post-vaccination antibody levels were higher and IFN-γ levels were lower in IIV sera compared to LAIV sera. Subjects who suffered breakthrough infections after IIV vaccination had higher levels of sCD25 compared to the control group. There were differences in LAIV post-vaccination interleukin levels for subjects who subsequently suffered breakthrough infections, but these differences were masked in subjects who received concomitant vaccines. Wide variances, sex-based differences and confounders such as concomitant vaccines thwart the establishment of specific cytokine responses as a correlate of protection, but our results provide real world evidence that the status of the immune system following vaccination is important for successful vaccination and subsequent protection against disease.

Catalytic ozonation of toluene over amorphous Cu-Mn bimetallic oxide: Influencing factors, degradation mechanism and pathways.

Herein, amorphous catalysts were employed to investigate the catalytic ozonation system, revealing the degradation mechanism and influencing factors (O3 concentration, temperature, and humidity) for toluene catalytic ozonation. Cu0.2MnOx exhibited the highest toluene oxidized and excellent stability (∼85% at 60 h) based on the suitable value of Oads/Olat and potent synergy between Cu with Mn. To explore the effect of factors, the change of fresh and post-reaction samples was compared as revealed in the relevant characterization results (SEM, XRD, BET, XPS, TGA), DRIFTS and GC-MS identified the intermediates and byproducts. The results show that appropriate temperature (100 °C) and O3 concentration (2100 ppm) can effectively enhance the number of reactive oxygen species. Although H2O can increase the production of ·OH to promote degradation, it is easier to quench the active sites on the surface of amorphous catalysts. During the reaction, the main role of Cu in Cu-Mn bimetallic oxides is adsorption of toluene and O3, formation of benzoic acid, and oxidation of short-chain products. As for the adjacent Mn, it works on the cleavage of O-O in O3 and the ring-opening of benzene. Then, the mainly catalytic ozonation pathway of toluene was proposed and followed the order: toluene, benzoic acid, benzene, maleic anhydride, short-chain carbon species, CO2, and H2O.

A review of the advances in catalyst modification using nonthermal plasma: Process, Mechanism and Applications.

With the continuous development of catalytic processes in chemistry, biology, organic synthesis, energy generation and many other fields, the design of catalysts with novel properties has become a new paradigm in both science and industry. Nonthermal plasma has aroused extensive interest in the synthesis and modification of catalysts. An increasing number of researchers are using plasma for the modification of target catalysts, such as modifying the dispersion of active sites, regulating electronic properties, enhancing metal-support interactions, and changing the morphology. Plasma provides an alternative choice for catalysts in the modification process of oxidation, reduction, etching, coating, and doping and is especially helpful for unfavourable thermodynamic processes or heat-sensitive reactions. This review focuses on the following points: (i) the fundamentals behind the nonthermal plasma modification of catalysts; (ii) the latest research progress on the application of plasma modified catalysts; and (iii) main challenges in the field and a vision for future development.

Antigenic comparison of the neuraminidases from recent influenza A vaccine viruses and 2019-2020 circulating strains.

Although viral-based influenza vaccines contain neuraminidase (NA or N) antigens from the recommended seasonal strains, NA is not extensively evaluated like hemagglutinin (H) during the strain selection process. Here, we compared the antigenicity of NAs from recently recommended H1N1 (2010-2021 seasons) and H3N2 (2015-2021 seasons) vaccine strains and viruses that circulated between September 2019 and December 2020. The antigenicity was evaluated by measuring NA ferret antisera titers that provide 50% inhibition of NA activity in an enzyme-linked lectin assay. Our results show that NAs from circulating H1N1 viruses and vaccine strains for the 2017-2021 seasons are all antigenically similar and distinct from the NA in the H1N1 strain recommended for the 2010-2017 seasons. Changes in N1 antigenicity were attributed to the accumulation of substitutions over time, especially the loss of an N-linked glycosylation site (Asn386) in current N1s. The NAs from circulating H3N2 viruses and the 2020-2021 vaccine strains showed similar antigenicity that varied across the N2s in the 2016-2020 vaccine strains and was distinct from the N2 in the 2015-2016 vaccine strain. These data suggest that the recent N1 antigenicity has remained similar since the loss of the head domain N-linked glycosylation site, whereas N2 antigenicity has changed more incrementally each season.

Bias at the third nucleotide of codon pairs in virus and host genomes.

Genomes of different sizes and complexity can be compared using common features. Most genomes contain open reading frames, and most genomes use the same genetic code. Redundancy in the genetic code means that different biases in the third nucleotide position of a codon exist in different genomes. However, the nucleotide composition of viruses can be quite different from host nucleotide composition making it difficult to assess the relevance of these biases. Here we show that grouping codons of a codon-pair according to the GC content of the first two nucleotide positions of each codon reveals patterns in nucleotide usage at the third position of the 1st codon. Differences between the observed and expected biases occur predominantly when the first two nucleotides of the 2nd codon are both S (strong, G or C) or both W (weak, A or T), not a mixture of strong and weak. The data indicates that some codon pairs are preferred because of the strength of the interactions between the codon and anticodon, the adjacent tRNAs and the ribosome. Using base-pairing strength and third position bias facilitates the comparison of genomes of different size and nucleotide composition and reveals patterns not previously described.

Investigation of Cu-Mn catalytic ozonation of toluene: Crystal phase, intermediates and mechanism.

The effect of different crystal phases, i.e. spinel phase (CuMn2O4) and amorphous phase (Cu0.2MnOx), was explored in Cu-Mn catalytic ozonation of toluene. The toluene removal efficiency followed the order of Cu0.2MnOx (91.2%) ˃ CuMn2O4 (74.5%) ˃ commercial catalyst Cu0.3MnOx (70.3%) in 130 min, and the higher CO2 yield (67.6%) could be also observed using Cu0.2MnOx. In order to investigate the effect of phases on the toluene degradation pathway, the intermediates and byproducts were identified by DRIFTS, GC-MS, and TOF-SIMS. No obvious difference was observed in the distribution of byproducts, except for the quantities, suggesting the discrepancy of oxidation rate. On the other hand, the catalysts were characterized before and after the ozonation process by TEM, BET, XPS, XRD, EPR, TGA, and TPR. It was proposed that for amorphous catalysts, the oxygen vacancy (Vo) helped the chemisorption of toluene, and adjacent Mn reacted as the main active site for the ozonation process. While, the redox pair of Cu+/Mn4+ and Cu2+/(Mn3+, Mn2+) in the spinel phase plays an important role in the generation of oxygen vacancies for O3 decomposition.

Universal influenza vaccine based on conserved antigens provides long-term durability of immune responses and durable broad protection against diverse challenge virus strains in mice.

Current influenza vaccines rely on inducing antibody responses to the rapidly evolving hemagglutinin (HA) and neuraminidase (NA) proteins, and thus need to be strain-matched. However, predictions of strains that will circulate are imperfect, and manufacturing of new vaccines based on them takes months. As an alternative, universal influenza vaccines target highly conserved antigens. In proof of concept studies of universal vaccine candidates in animal models challenge is generally conducted only a short time after vaccination, but protective immunity lasting far longer is important for the intended public health impact. We address the challenge of providing long-term protection. We demonstrate here broad, powerful, and long-lasting immune protection for a promising universal vaccine candidate. A single intranasal dose of recombinant adenoviruses (rAd) expressing influenza A nucleoprotein (A/NP) and matrix 2 (M2) was used. Extending our previous studies of this type of vaccine, we show that antibody and T-cell responses persist for over a year without boosting, and that protection against challenge persists a year after vaccination and remains broad, covering both group 1 and 2 influenza A viruses. In addition, we extend the work to influenza B. Immunization with influenza B nucleoprotein (B/NP)-rAd also gives immune responses that last a year without boosting and protect against challenge with influenza B viruses of mismatched HA lineages. Despite host immunity to adenoviral antigens, effective readministration is possible a year after primary vaccination, as shown by successful immunization to a transgene product the animals had not seen before. Protection against challenge with divergent and highly pathogenic A/H7N9 virus was weaker but was enhanced by a second dose of vaccine. Thus, this mucosal vaccination to conserved influenza antigens confers very long-lasting immune protection in animals against a broad range of influenza A and B viruses.

A Codon-Pair Bias Associated With Network Interactions in Influenza A, B, and C Genomes.

A new codon-pair bias present in the genomes of different types of influenza virus is described. Codons with fewer network interactions are more frequency paired together than other codon-pairs in influenza A, B, and C genomes. A shared feature among three different influenza types suggests an evolutionary bias. Codon-pair preference can affect both speed of protein translation and RNA structure. This newly identified bias may provide insight into drivers of virus evolution.

Balancing the influenza neuraminidase and hemagglutinin responses by exchanging the vaccine virus backbone.

Virions are a common antigen source for many viral vaccines. One limitation to using virions is that the antigen abundance is determined by the content of each protein in the virus. This caveat especially applies to viral-based influenza vaccines where the low abundance of the neuraminidase (NA) surface antigen remains a bottleneck for improving the NA antibody response. Our systematic analysis using recent H1N1 vaccine antigens demonstrates that the NA to hemagglutinin (HA) ratio in virions can be improved by exchanging the viral backbone internal genes, especially the segment encoding the polymerase PB1 subunit. The purified inactivated virions with higher NA content show a more spherical morphology, a shift in the balance between the HA receptor binding and NA receptor release functions, and induce a better NA inhibitory antibody response in mice. These results indicate that influenza viruses support a range of ratios for a given NA and HA pair which can be used to produce viral-based influenza vaccines with higher NA content that can elicit more balanced neutralizing antibody responses to NA and HA.

Highly pathogenic avian influenza A/Guangdong/17SF003/2016 is immunogenic and induces cross-protection against antigenically divergent H7N9 viruses.

Avian influenza A(H7N9) epidemics have a fatality rate of approximately 40%. Previous studies reported that low pathogenic avian influenza (LPAI)-derived candidate vaccine viruses (CVVs) are poorly immunogenic. Here, we assess the immunogenicity and efficacy of a highly pathogenic avian influenza (HPAI) A/Guangdong/17SF003/2016 (GD/16)-extracted hemagglutinin (eHA) vaccine. GD/16 eHA induces robust H7-specific antibody responses in mice with a marked adjuvant antigen-sparing effect. Mice immunized with adjuvanted GD/16 eHA are protected from the lethal LPAI and HPAI H7N9 challenges, in stark contrast to low antibody titers and high mortality in mice receiving adjuvanted LPAI H7 eHAs. The protection correlates well with the magnitude of the H7-specific antibody response (IgG and microneutralization) or HA group 2 stem-specific IgG. Inclusion of adjuvanted GD/16 eHA in heterologous prime-boost improves the immunogenicity and protection of LPAI H7 HAs in mice. Our findings support the inclusion of GD/16-derived CVV in the pandemic preparedness vaccine stockpile.

Reduced Influenza B-Specific Postvaccination Antibody Cross-reactivity in the B/Victoria Lineage-Predominant 2019/20 Season.

BACKGROUND: The influenza activity of the 2019/20 season remained high and widespread in the United States with type B viruses predominating the early season. The majority of B viruses characterized belonged to B/Victoria (B/Vic) lineage and contained a triple deletion of amino acid (aa) 162-164 in hemagglutinin (3DEL). These 3DEL viruses are antigenically distinct from B/Colorado/06/2017 (CO/06)-the B/Vic vaccine component of the 2018/19 and 2019/20 seasons representing the viruses with a double deletion of aa 162-163 in hemagglutinin (2DEL). METHODS: We performed molecular characterization and phylogenetic analysis of circulating B/Vic viruses. We also conducted hemagglutination inhibition (HAI) assay using archived human postvaccination sera collected from healthy subjects administered with different types of 2018/19 or 2019/20 seasonal vaccines. Their HAI cross-reactivity to representative 3DEL viruses was analyzed. RESULTS: The CO/06-specific human postvaccination sera, after being adjusted for vaccine type, had significantly reduced HAI cross-reactivity toward representative 3DEL viruses, especially the 136E+150K subgroup. The geometric mean titers against 3DEL viruses containing 136E+150K mutations were 1.6-fold lower in all populations (P = .051) and 1.9-fold lower in adults (P = .016) compared with those against the 136E+150N viruses. CONCLUSIONS: Our results indicate that postvaccination antibodies induced by the B/Vic vaccine component of the 2019/20 influenza season had reduced HAI cross-reactivity toward predominant 3DEL viruses in the United States. A close monitoring of the 3DEL 136E+150K subgroup is warranted should this subgroup return and predominate the 2020/21 influenza season.

A novel pilot-scale installation integrated of improved sieve-tray tower and wet electrostatic precipitator for paint mist removal.

In order to overcome the problem of decrease of the spraying exhausts purification efficiency caused by the paint mist, the installation combining of the improved sieve-tray tower and the wet electrostatic precipitator (WEP) was used for the treatment of the pilot-scale 1,000 m3 paint waste gas. The characteristics of paint mist were investigated, showing that the size distribution of oil-based paint mist located in the range of 5.4-43.4 µm with an approximate symmetrical distribution under the pressure of 0.4 MPa. The size of paint mist less than 10 µm accounted for ~50% in quantity. It was revealed that the integrated setup was able to remove the concentration of oil-based paint mist with ~98% removal efficiency, in which the improved sieve-tray tower contributed ~94% particles removal. The soluble volatile organic pollutants (VOCs) of spraying exhaust gas were also captured by sieve-tray tower, promoting VOCs removal. At last, the feasibility of integrated setup used in paint mist removal was analyzed, including the secondary pollutants treatment. The results exhibited the setup has the potential for industrial applications.Implications: Fabricating a pilot-scale installation integrated of the improved sieve-tray tower and wet electrostatic precipitator to remove spraying exhaust gas in the furniture factory efficiently. This tech meets China's VOC emission policy.

Insights from the comparison of genomic variants from two influenza B viruses grown in the presence of human antibodies in cell culture.

Understanding the extent and limitation of viral genome evolution can provide insight about potential drug and vaccine targets. Influenza B Viruses (IBVs) infect humans in a seasonal manner and causes significant morbidity and mortality. IBVs are negative-sense single-stranded RNA viruses with a segmented genome and can be divided into two antigenically distinct lineages. The two lineages have been circulating and further evolving for almost four decades. The immune response to IBV infection can lead to antibodies that target the strain causing the infection. Some antibodies are cross-reactive and are able to bind strains from both lineages but, because of antigenic drift and immunodominance, both lineages continue to evolve and challenge human health. Here we investigate changes in the genomes of an IBVs from each lineage after passage in tissue culture in the presence of human sera containing polyclonal antibodies directed toward antigenically and temporally distinct viruses. Our previous analysis of the fourth segment, which encodes the major surface protein HA, revealed a pattern of change in which signature sequences from one lineage mutated to the signature sequences of the other lineage. Here we analyze genes from the other genomic segments and observe that most of the quasispecies' heterogeneity occurs at the same loci in each lineage. The nature of the variants at these loci are investigated and possible reasons for this pattern are discussed. This work expands our understanding of the extent and limitations of genomic change in IBV.

Immune Pressure on Polymorphous Influenza B Populations Results in Diverse Hemagglutinin Escape Mutants and Lineage Switching.

Mutations arise in the genomes of progeny viruses during infection. Mutations that occur in epitopes targeted by host antibodies allow the progeny virus to escape the host adaptive, B-cell mediated antibody immune response. Major epitopes have been identified in influenza B virus (IBV) hemagglutinin (HA) protein. However, IBV strains maintain a seasonal presence in the human population and changes in IBV genomes in response to immune pressure are not well characterized. There are two lineages of IBV that have circulated in the human population since the 1980s, B-Victoria and B-Yamagata. It is hypothesized that early exposure to one influenza subtype leads to immunodominance. Subsequent seasonal vaccination or exposure to new subtypes may modify subsequent immune responses, which, in turn, results in selection of escape mutations in the viral genome. Here we show that while some mutations do occur in known epitopes suggesting antibody escape, many mutations occur in other parts of the HA protein. Analysis of mutations outside of the known epitopes revealed that these mutations occurred at the same amino acid position in viruses from each of the two IBV lineages. Interestingly, where the amino acid sequence differed between viruses from each lineage, reciprocal amino acid changes were observed. That is, the virus from the Yamagata lineage become more like the Victoria lineage virus and vice versa. Our results suggest that some IBV HA sequences are constrained to specific amino acid codons when viruses are cultured in the presence of antibodies. Some changes to the known antigenic regions may also be restricted in a lineage-dependent manner. Questions remain regarding the mechanisms underlying these results. The presence of amino acid residues that are constrained within the HA may provide a new target for universal vaccines for IBV.